Path parameters

Query parameters

The maximum number of results per page that should be returned. If the number of available results is larger than maxResults, Compute Engine returns a nextPageToken that can be used to get the next page of results in subsequent list requests. Acceptable values are 0 to 500, inclusive. (Default: 500)

pageToken

string

Specifies a page token to use. Set pageToken to the nextPageToken returned by a previous list request to get the next page of results.

filter

string

A filter expression that filters resources listed in the response. The expression must specify the field name, a comparison operator, and the value that you want to use for filtering. The value must be a string, a number, or a boolean. The comparison operator must be either =, !=, >, or <.

For example, if you are filtering Compute Engine instances, you can exclude instances named example-instance by specifying name != example-instance.

You can also filter nested fields. For example, you could specify scheduling.automaticRestart = false to include instances only if they are not scheduled for automatic restarts. You can use filtering on nested fields to filter based on resource labels.

To filter on multiple expressions, provide each separate expression within parentheses. For example, (scheduling.automaticRestart = true) (cpuPlatform = "Intel Skylake"). By default, each expression is an AND expression. However, you can include AND and OR expressions explicitly. For example, (cpuPlatform = "Intel Skylake") OR (cpuPlatform = "Intel Broadwell") AND (scheduling.automaticRestart = true).

orderBy

string

Sorts list results by a certain order. By default, results are returned in alphanumerical order based on the resource name.

You can also sort results in descending order based on the creation timestamp using orderBy="creationTimestamp desc". This sorts results based on the creationTimestamp field in reverse chronological order (newest result first). Use this to sort resources like operations so that the newest operation is returned first.

Currently, only sorting by name or creationTimestamp desc is supported.

Request body

The request body must be empty.

Response body

If successful, the response body contains data with the following structure:

Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.

items[].description

string

An optional description of this resource. Provide this property when you create the resource.

items[].target

string

URL of the managed instance group that this autoscaler will scale.

items[].autoscalingPolicy

object

The configuration parameters for the autoscaling algorithm. You can define one or more of the policies for an autoscaler: cpuUtilization, customMetricUtilizations, and loadBalancingUtilization.

If none of these are specified, the default will be to autoscale based on cpuUtilization to 0.6 or 60%.

items[].autoscalingPolicy.minNumReplicas

number

The minimum number of replicas that the autoscaler can scale down to. This cannot be less than 0. If not provided, autoscaler will choose a default value depending on maximum number of instances allowed.

items[].autoscalingPolicy.maxNumReplicas

number

The maximum number of instances that the autoscaler can scale up to. This is required when creating or updating an autoscaler. The maximum number of replicas should not be lower than minimal number of replicas.

items[].autoscalingPolicy.coolDownPeriodSec

number

The number of seconds that the autoscaler should wait before it starts collecting information from a new instance. This prevents the autoscaler from collecting information when the instance is initializing, during which the collected usage would not be reliable. The default time autoscaler waits is 60 seconds.

Virtual machine initialization times might vary because of numerous factors. We recommend that you test how long an instance may take to initialize. To do this, create an instance and time the startup process.

items[].autoscalingPolicy.cpuUtilization

object

Defines the CPU utilization policy that allows the autoscaler to scale based on the average CPU utilization of a managed instance group.

items[].autoscalingPolicy.cpuUtilization.utilizationTarget

number

The target CPU utilization that the autoscaler should maintain. Must be a float value in the range (0, 1]. If not specified, the default is 0.6.

If the CPU level is below the target utilization, the autoscaler scales down the number of instances until it reaches the minimum number of instances you specified or until the average CPU of your instances reaches the target utilization.

If the average CPU is above the target utilization, the autoscaler scales up until it reaches the maximum number of instances you specified or until the average utilization reaches the target utilization.

items[].autoscalingPolicy.customMetricUtilizations[]

object

Configuration parameters of autoscaling based on a custom metric.

items[].autoscalingPolicy.customMetricUtilizations[].metric

string

The identifier (type) of the Stackdriver Monitoring metric. The metric cannot have negative values.

The target value of the metric that autoscaler should maintain. This must be a positive value. A utilization metric scales number of virtual machines handling requests to increase or decrease proportionally to the metric.

For example, a good metric to use as a utilizationTarget is www.googleapis.com/compute/instance/network/received_bytes_count. The autoscaler will work to keep this value constant for each of the instances.

Defines how target utilization value is expressed for a Stackdriver Monitoring metric. Either GAUGE, DELTA_PER_SECOND, or DELTA_PER_MINUTE.

items[].autoscalingPolicy.loadBalancingUtilization

object

Configuration parameters of autoscaling based on load balancer.

items[].autoscalingPolicy.loadBalancingUtilization.utilizationTarget

number

Fraction of backend capacity utilization (set in HTTP(S) load balancing configuration) that autoscaler should maintain. Must be a positive float value. If not defined, the default is 0.8.

items[].zone

string

[Output Only] URL of the zone where the instance group resides (for autoscalers living in zonal scope).

items[].region

string

[Output Only] URL of the region where the instance group resides (for autoscalers living in regional scope).

items[].selfLink

string

[Output Only] Server-defined URL for the resource.

items[].status

enum

[Output Only] The status of the autoscaler configuration.

items[].statusDetails[]

object

[Output Only] Human-readable details about the current state of the autoscaler. Read the documentation for Commonly returned status messages for examples of status messages you might encounter.

items[].statusDetails[].message

string

The status message.

items[].statusDetails[].type

enum

The type of error returned.

items[].kind

string

[Output Only] Type of the resource. Always compute#autoscaler for autoscalers.

nextPageToken

string

[Output Only] This token allows you to get the next page of results for list requests. If the number of results is larger than maxResults, use the nextPageToken as a value for the query parameter pageToken in the next list request. Subsequent list requests will have their own nextPageToken to continue paging through the results.

selfLink

string

[Output Only] Server-defined URL for this resource.

warning

object

[Output Only] Informational warning message.

warning.code

enum

[Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.

warning.message

string

[Output Only] A human-readable description of the warning code.

warning.data[]

object

[Output Only] Metadata about this warning in key: value format. For example:

"data": [ { "key": "scope", "value": "zones/us-east1-d" }

warning.data[].key

string

[Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).